I justify the 'Scare Tactics' ending just by pointing out the episode would have been a LOT more awful if the emos were ACTUALLY plants. That makes the twist 100% justifiable to me.

Emos are the most fear thing only for gothics, I think, as well shaking plants, if not a ficus with a motor inside, for everybody .

And for horror movie and plants versus south park, M&T likes to use this reference coming from the 60's horror twilight zone movies. These were movies that represented our fears for the unknow/WW2/cold war. And M&T abuses on it.

About the music just after the intro, Iswear that I tried... but couldn't found the name of the music.

How I see it: the goths are under attack by the asians and their only hope is to ally with the vamp kids(romans). They both have a common enemy. The asians are turning the goths and vamps into emos (contemporary white people). Even Michael's mom is asian and she wants to turn him into a "normal kid". The goth kids know they had raided vamp kids (roman) territories before (they burned the Hot Topic) but they risk everything and go straight into the vamp group to warn them about the common threat. The little goth kid tells his friend to kill him if he ever turns into an emo (the goths would rather die than become slaves). The woman at the child protection represents the ignorant people who think that goths, vamps and emos are all the same. They think the romans are the people living in France, Spain, etc. and the goths are the people living in Sweden, Germany, Ukraine, etc. but the goths and the romans have nothing to do with the cock sucking emos living in our times. So, goths and vamps are not the same as emos, the goths and the romans are different from the decaying white race living in our times.